EP0087609B1 - Heat resisting nickel-iron alloys for castings with a highly stable structure - Google Patents

Heat resisting nickel-iron alloys for castings with a highly stable structure Download PDF

Info

Publication number
EP0087609B1
EP0087609B1 EP83101057A EP83101057A EP0087609B1 EP 0087609 B1 EP0087609 B1 EP 0087609B1 EP 83101057 A EP83101057 A EP 83101057A EP 83101057 A EP83101057 A EP 83101057A EP 0087609 B1 EP0087609 B1 EP 0087609B1
Authority
EP
European Patent Office
Prior art keywords
alloy according
alloy
eff
resistance
castings
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP83101057A
Other languages
German (de)
French (fr)
Other versions
EP0087609A1 (en
Inventor
Helmut Dr.-Ing. Brandis
Wolfgang Dr.-Ing. Spyra
Josef Reismann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thyssen Stahl AG
Original Assignee
Thyssen Edelstahlwerke AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thyssen Edelstahlwerke AG filed Critical Thyssen Edelstahlwerke AG
Publication of EP0087609A1 publication Critical patent/EP0087609A1/en
Application granted granted Critical
Publication of EP0087609B1 publication Critical patent/EP0087609B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C30/00Alloys containing less than 50% by weight of each constituent
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C19/00Alloys based on nickel or cobalt
    • C22C19/03Alloys based on nickel or cobalt based on nickel
    • C22C19/05Alloys based on nickel or cobalt based on nickel with chromium
    • C22C19/051Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
    • C22C19/055Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 20% but less than 30%
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S376/00Induced nuclear reactions: processes, systems, and elements
    • Y10S376/90Particular material or material shapes for fission reactors

Definitions

  • the invention relates to a highly heat-resistant, temperature-insensitive, cobalt-free nickel-iron casting alloy with great thermodynamic stability of the structural components, which also has high thermal hardness, excellent resistance to oxidation, corrosion and wear as well as good welding properties and is particularly suitable as a material for nuclear reactor components .
  • alloys that can be used for example, in the flange area of nuclear reactors, the following limit values are required for certain accompanying elements: Co ⁇ 0.1%, B ⁇ 0.01%, Ta ⁇ 0.002%.
  • Iron-based alloys can generally only be used to a limited extent due to their low heat resistance and poor corrosion resistance.
  • Nickel-chromium-boron-silicon alloys cannot be used due to their insufficient toughness and corrosion resistance, so that their advantages, such as a low melting temperature range, cannot be exploited.
  • the object of the invention is to propose a structurally stable, heat-resistant nickel-iron cast alloy which, with otherwise the same good properties as that of the aforementioned alloy according to DE-PS27 14 674, has better scale resistance similar to that of cobalt alloys.
  • the inventive alloy differs from the known alloy according to DE-PS 27 14 674 in that the tungsten content is absent and the molybdenum content is increased. Tungsten is comparatively more expensive and more uncertainly available than molybdenum. Furthermore, the known alloy can be iron-free or have a maximum content of 59.3% Fe, while in the alloy according to the invention the iron content is narrowly limited at 18 to 26% with a view to achieving the required properties. The same applies to the chromium content, which must be present in amounts of 22 to 26%. Chromium dissolved in the mixed crystal primarily ensures great resistance to oxidation and corrosion, while the chromium bonded in the carbide also determines the wear resistance. For reasons of toughness, the formation of coarse primary carbides was counteracted by the upper limit of the chromium content. Higher chromium levels also deteriorate the welding behavior in an unacceptable manner.
  • Molybdenum in amounts of 12.5 to 14.5% in the alloy according to the invention when it is dissolved in the mixed crystal, improves the heat resistance and corrosion resistance and, in the carbide, improves the wear resistance.
  • a replacement of the carbide and intermetallic tungsten phase by the molybdenum, which does not necessarily have the same phase, is not taught by the D-PS 27 14 674, rather the known teaching is to provide a minimum content of 1.5% tungsten. Nor could it have been foreseen that the absence of tungsten in the alloy would result in the considerable improvement in scale resistance to be described below.
  • DE-PS 27 14 674 does not reveal the knowledge on which the invention is based, that by carefully limiting the mutually influencing elements nickel, iron, chromium and molybdenum, the catastrophic oxidation otherwise frequently observed on materials containing high molybdenum due to the formation of volatile oxides is omitted. It was therefore not foreseeable that by exceeding the maximum content of 12% for molybdenum specified in DE-PS 27 14 674, not only the same but significantly improved scale resistance can be achieved.
  • the carbon required for carbide formation has to meet a minimum value to achieve good sweat properties and is limited to a maximum value of 1.6% in order to avoid the formation of coarse primary carbides and to ensure sufficient hardness.
  • Manganese serves as a deoxidizer and desulfurization agent, but is limited to a maximum of 0.2% in order to avoid pore formation in the casting or weld metal.
  • Silicon increases the corrosion resistance in acidic reduced solutions and promotes the flow behavior in the liquid phase.
  • Niobium / tantalum is added to refine the grain.
  • the shape of the special carbides is controlled by suitable deoxidizing agents such as calcium, magnesium, aluminum, zirconium and rare earth metals.
  • the structure of the alloy according to the invention consists of primary dendrites with a cubic-bottle-centered structure and residual melt neectics, which are composed of mixed crystals and carbides of the types M, C 3 and M s C.
  • FIG. 2 shows this.
  • FIG. 2a shows the structure in 1000 times magnification for the rapidly quenched cast state
  • FIG. 2b shows the structure after a subsequent 1000-hour annealing at 600 ° C. Changes in structure are imperceptible.
  • the composition of the alloy according to the invention used in the tests shown in FIGS. 1 to 3 was as follows:
  • the structural stability is confirmed by hardness measurements. Since the application temperatures in the flange area of nuclear reactors are 350 ° C and sometimes even 500 ° C in the event of a malfunction, the hardness of cast and TIG weld metal was determined between staggered annealing between 350 and 600 ° C. 3 shows the relatively narrow scatter band of hardness with values between 45 and 48 HRC for annealing times up to 1000 h. The hardness is accordingly determined by the primary structure of the alloy according to the invention. Aging processes are not indicated in the hardness course up to 600 ° C.
  • the alloy according to the invention was tested with the commercially available cobalt base alloy, material no. 3177.0 compared.
  • the materials examined had the following composition:
  • the alloy according to the invention has a superior warm hardness up to at least 900 ° C. compared to the known cobalt alloy.
  • the comparatively large resistance to deformation at high temperature is characteristic of the heat resistance of the alloy according to the invention.
  • the resistance to temperature changes is favorably influenced by a large modulus of elasticity and small coefficients of expansion (FIG. 5).
  • the nickel alloy according to the invention has a smaller coefficient of expansion and a greater modulus of elasticity than the known cobalt alloy used for comparison.
  • the resistance of the claimed nickel alloy to oxidation is high, as shown in FIG. 6.
  • the oxidation behavior of the new alloy up to 900 ° C is the same as that of the cobalt alloy.
  • the commercially available alloy according to DE-PS 2714674 has a tendency to catastrophic oxidation, as can be seen from the sharp increase in oxidation above 800 ° C.
  • the alloy according to the invention is particularly suitable for nuclear reactor components and for armoring valves.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Arc Welding In General (AREA)
  • Heat Treatment Of Steel (AREA)

Description

Die Erfindung betrifft eine hochwarmfeste, gegen Temperaturwechsel unempfindliche, kobaltfreie Nickel-Eisen-G usslegieru ng mit grosser thermodynamischer Stabilität der Gefügebestandteile, die zudem hohe Wärmehärte, hervorragende Beständigkeit gegen Oxidation, Korrosion und Verschleiss sowie gute Schweisseigenschaften aufweist und sich insbesondere als Werkstoff für Kernreaktorbauteile eignet.The invention relates to a highly heat-resistant, temperature-insensitive, cobalt-free nickel-iron casting alloy with great thermodynamic stability of the structural components, which also has high thermal hardness, excellent resistance to oxidation, corrosion and wear as well as good welding properties and is particularly suitable as a material for nuclear reactor components .

An Legierungen, die beispielsweise im Flanschbereich von Kernreaktoren einsetzbar sind, werden für bestimmte Begleitelemente folgende Grenzwerte gefordert: Co < 0,1%, B < 0,01 %, Ta < 0,002%.For alloys that can be used, for example, in the flange area of nuclear reactors, the following limit values are required for certain accompanying elements: Co <0.1%, B <0.01%, Ta <0.002%.

Eisenbasislegierungen sind in der Regel wegen geringer Warmfestigkeit und mangelnder Korrosionsbeständigkeit nur bedingt verwendbar.Iron-based alloys can generally only be used to a limited extent due to their low heat resistance and poor corrosion resistance.

Nickel-Chrom-Bor-Silizium-Legierungen kommen wegen ungenügender Zähigkeit und Korrosionsbeständigkeit nicht in Betracht, so dass deren Vorteile, wie niedriger Schmelztemperaturbereich, nicht ausgenutzt werden können.Nickel-chromium-boron-silicon alloys cannot be used due to their insufficient toughness and corrosion resistance, so that their advantages, such as a low melting temperature range, cannot be exploited.

Aus der DE-PS 27 14 674 ist eine für Kernreaktor-Bauteile geeignete Legierung auf Nickelbasis mit 0,2 bis 1,9% C, 18 bis 32% Cr, 1,5 bis 8% W, 6 bis 12% Mo und Fakultativzusätzen von bis 2% Si, je bis 3% Mn, Nb/Ta, Zr, V und bis 0,9% B, Rest 15 bis40% Ni mit guter Kalt- und Warmhärte, guter Korrosionsbeständigkeit und Reibeigenschaft sowie Schweissbarkeit und hoher Dauerfestigkeit bekannt.From DE-PS 27 14 674 a suitable for nuclear reactor components nickel-based alloy with 0.2 to 1.9% C, 18 to 32% Cr, 1.5 to 8% W, 6 to 12% Mo and optional additives of up to 2% Si, each up to 3% Mn, Nb / Ta, Zr, V and up to 0.9% B, rest 15 to 40% Ni with good cold and warm hardness, good corrosion resistance and friction properties as well as weldability and high fatigue strength.

Aufgabe der Erfindung ist es, eine gefügestabile hochwarmfeste Nickel-Eisen-Gusslegierung vorzuschlagen, die bei sonst gleichen guten Eigenschaften wie die der vorerwähnten Legierung gemäss DE-PS27 14 674 bessere Zunderbeständigkeit ähnlich der von Kobaltlegierungen hat.The object of the invention is to propose a structurally stable, heat-resistant nickel-iron cast alloy which, with otherwise the same good properties as that of the aforementioned alloy according to DE-PS27 14 674, has better scale resistance similar to that of cobalt alloys.

Zur Lösung dieser Aufgabe wird erfindungsgemäss eine Legierung der in den Ansprüchen gekennzeichneten Zusammensetzung vorgeschlagen. Vorteilhafte Ausgestaltungen sind in den Unteransprüchen gekennzeichnet.To achieve this object, an alloy of the composition characterized in the claims is proposed. Advantageous refinements are characterized in the subclaims.

Von der bekannten Legierung gemäss DE-PS 27 14 674 unterscheidet sich die erfindungsgemässe in einem fehlenden Gehalt an Wolfram und einem erhöhten Gehalt an Molybdän. Wolfram ist vergleichsweise kostenaufwendiger und zudem unsicherer verfügbar als Molybdän. Ferner kann die bekannte Legierung eisenfrei sein bzw. einen Maximalgehalt von 59,3% Fe aufweisen, während bei der erfindungsgemässen Legierung der Eisengehalt mit 18 bis 26% im Hinblick auf die Erzielung der geforderten Eigenschaften eng begrenzt ist. Das gleiche gilt für den Gehalt an Chrom, das in Mengen von 22 bis 26% vorzuliegen hat. Im Mischkristall gelöstes Chrom sorgt vornehmlich für grosse Oxidations- und Korrosionsbeständigkeit, während das im Karbid abgebundene Chrom zusätzlich den Verschleisswiderstand bestimmt. Der Bildung grober Primärkarbide wurde aus Zähigkeitsgründen durch die obere Grenze des Chromgehalts entgegengewirkt. Höhere Chromgehalte verschlechtern ausserdem in nicht tragbarer Weise das Schweissverhalten.The inventive alloy differs from the known alloy according to DE-PS 27 14 674 in that the tungsten content is absent and the molybdenum content is increased. Tungsten is comparatively more expensive and more uncertainly available than molybdenum. Furthermore, the known alloy can be iron-free or have a maximum content of 59.3% Fe, while in the alloy according to the invention the iron content is narrowly limited at 18 to 26% with a view to achieving the required properties. The same applies to the chromium content, which must be present in amounts of 22 to 26%. Chromium dissolved in the mixed crystal primarily ensures great resistance to oxidation and corrosion, while the chromium bonded in the carbide also determines the wear resistance. For reasons of toughness, the formation of coarse primary carbides was counteracted by the upper limit of the chromium content. Higher chromium levels also deteriorate the welding behavior in an unacceptable manner.

Molybdän in Mengen von 12,5 bis 14,5% verbessert in der erfindungsgemässen Legierung, wenn es im Mischkristall gelöst ist, die Warmfestigkeit und Korrosionsbeständigkeit und, im Karbid abgebunden, den Verschleisswiderstand. Einen Ersatz des Bildners von Karbid und intermetallischer Phasen Wolfram durch den Bildner nicht unbedingt gleicher Phasen Molybdän lehrt die D E- PS 27 14 674 nicht, vielmehr geht die bekannte Lehre dahin, einen Mindestgehalt von 1,5% Wolfram vorzusehen. Es war auch nicht vorherzusehen, dass bei einem Fehlen von Wolfram in der Legierung die nachfolgend noch näher zu schildernde beträchtliche Verbesserung der Zunderbeständigkeiteintreten würde. Darüber hinaus ist der DE-PS 27 14 674 die der Erfindung zugrunde liegende Erkenntnis nicht zu entnehmen, dass durch sorgfältige Begrenzung der sich gegenseitig beeinflussenden Elemente Nickel, Eisen, Chrom und Molybdän die an hochmolybdänhaltigen Werkstoffen sonst häufig zu beobachtende katastrophale Oxidation durch Entstehen flüchtiger Oxide unterbleibt. Es war also nicht vorherzusehen, dass durch das Überschreiten des in der DE-PS 27 14 674 angegebenen Maximalgehalts für Molybdän von 12% nicht nur gleiche, sondern wesentlich verbesserte Zunderbeständigkeit erzielt werden kann.Molybdenum in amounts of 12.5 to 14.5% in the alloy according to the invention, when it is dissolved in the mixed crystal, improves the heat resistance and corrosion resistance and, in the carbide, improves the wear resistance. A replacement of the carbide and intermetallic tungsten phase by the molybdenum, which does not necessarily have the same phase, is not taught by the D-PS 27 14 674, rather the known teaching is to provide a minimum content of 1.5% tungsten. Nor could it have been foreseen that the absence of tungsten in the alloy would result in the considerable improvement in scale resistance to be described below. In addition, DE-PS 27 14 674 does not reveal the knowledge on which the invention is based, that by carefully limiting the mutually influencing elements nickel, iron, chromium and molybdenum, the catastrophic oxidation otherwise frequently observed on materials containing high molybdenum due to the formation of volatile oxides is omitted. It was therefore not foreseeable that by exceeding the maximum content of 12% for molybdenum specified in DE-PS 27 14 674, not only the same but significantly improved scale resistance can be achieved.

Der zur Karbidbildung benötigte Kohlenstoff hat einem Mindestwert zur Erzielung guter Schweissegenschaft zu genügen und ist auf einen Höchstwert von 1,6% begrenzt, um die Bildung grober Primärkarbide zu vermeiden und um ausreichende Härte zu gewährleisten.The carbon required for carbide formation has to meet a minimum value to achieve good sweat properties and is limited to a maximum value of 1.6% in order to avoid the formation of coarse primary carbides and to ensure sufficient hardness.

Von besonderer Bedeutung ist auch der effektive Kohlenstoffgehalt, der nach der Formel

  • % Ceff = % C + 0,86 x % N + 1,11 x % B

zwischen 1,1 und 1,6 liegen soll. Dabei erreicht die Härte bei einem effektiven Kohlenstoffgehalt von etwa 1,3% einen Grösstwert (Fig. 1).The effective carbon content according to the formula is also of particular importance
  • % C eff = % C + 0.86 x % N + 1.11 x% B

should be between 1.1 and 1.6. The hardness reaches a maximum value with an effective carbon content of about 1.3% (FIG. 1).

Mangan dient als Desoxidations- und Entschwefelungsmittel, ist jedoch begrenzt auf maximal 0,2%, um Porenbildung im Guss oder Schweissgut zu vermeiden.Manganese serves as a deoxidizer and desulfurization agent, but is limited to a maximum of 0.2% in order to avoid pore formation in the casting or weld metal.

Silizium erhöht die Korrosionsbeständigkeit in sauren reduzierten Lösungen und begünstigt das Fliessverhalten in flüssiger Phase.Silicon increases the corrosion resistance in acidic reduced solutions and promotes the flow behavior in the liquid phase.

Niob/Tantal wird zur Kornverfeinerung zugesetzt.Niobium / tantalum is added to refine the grain.

Durch geeignete Desoxidationsmittel wie Kalzium, Magnesium, Aluminium, Zirkonium und seltene Erdmetalle wird die Form der Sonderkarbide gesteuert.The shape of the special carbides is controlled by suitable deoxidizing agents such as calcium, magnesium, aluminum, zirconium and rare earth metals.

Das Gefüge der erfindungsgemässen Legierung besteht nach metallografischer und röntgenografischer Untersuchung aus Primärdendriten mit kubischfläschenzentrierter Struktur und Restschmelzneutektikum, das sich aus Mischkristall und Karbiden vom Typ M,C3 sowie MsC zusammensetzt.According to metallographic and X-ray examination, the structure of the alloy according to the invention consists of primary dendrites with a cubic-bottle-centered structure and residual melt neectics, which are composed of mixed crystals and carbides of the types M, C 3 and M s C.

Zwischen 350 und 600° C weist die erfindungsgemässe Legierung eine überraschend hohe thermodynamische Stabilität auf. Fig. 2 belegt dies. Fig. 2a zeigt das Gefüge in 1000-facher Vergrösserung für den schnell abgeschreckten Gusszustand, während Fig. 2b den Gefügezustand nach eine anschliessenden 1000 h-Glühung bei 600° C zeigt. Gefügeänderungen sind nicht wahrnehmbar. Die Zusammensetzung der bei den in den Figuren 1 bis 3 wiedergegebenen Versuchen eingesetzten erfindungsgemässen Legierung (in Gew.- %) war wie folgt:Between 350 and 600 ° C has the Invention alloy has surprisingly high thermodynamic stability. Fig. 2 shows this. FIG. 2a shows the structure in 1000 times magnification for the rapidly quenched cast state, while FIG. 2b shows the structure after a subsequent 1000-hour annealing at 600 ° C. Changes in structure are imperceptible. The composition of the alloy according to the invention used in the tests shown in FIGS. 1 to 3 (in% by weight) was as follows:

Figure imgb0001
Figure imgb0001

Die Gefügestabilität wird durch Härtemessungen bestätigt. Da im Flanschbereich von Kernreaktoren die Anwendungstemperaturen bei 350° C und im Störfalle zeitweise sogar bei 500° C liegen, wurde die Härte an Guss- und WIG-Schweissgut nach zeitlich gestaffelten Glühungen zwischen 350 und 600° C ermittelt. Fig. 3 zeigt das relativ schmale Streuband der Härte mit Werten zwischen 45 und 48 HRC für Glühzeiten bis 1000 h. Die Härte wird demnach durch das Primärgefüge der erfindungsgemässen Legierung bestimmt. Überalterungsvorgänge deuten sich bis 600° C im Härteverlauf nicht an.The structural stability is confirmed by hardness measurements. Since the application temperatures in the flange area of nuclear reactors are 350 ° C and sometimes even 500 ° C in the event of a malfunction, the hardness of cast and TIG weld metal was determined between staggered annealing between 350 and 600 ° C. 3 shows the relatively narrow scatter band of hardness with values between 45 and 48 HRC for annealing times up to 1000 h. The hardness is accordingly determined by the primary structure of the alloy according to the invention. Aging processes are not indicated in the hardness course up to 600 ° C.

In weiteren Untersuchungen wurde die erfindungsgemässe Legierung mit der handelsüblichen Köbaltbasislegierung, Werkstoff-Nr. 3177.0 verglichen. Die untersuchten Werkstoffe hatten folgende Zusammensetzung:

Figure imgb0002
In further investigations, the alloy according to the invention was tested with the commercially available cobalt base alloy, material no. 3177.0 compared. The materials examined had the following composition:
Figure imgb0002

Fig. 4 zeigt, dass die erfindungsgemässe Legierung gegenüber der bekannten Kobaltlegierung bis mindestens 900° C eine überlegene Warmhärte aufweist. Der vergleichsweise grosse Formänderungswiderstand bei hoher Temperatur ist kennzeichnend für die Warmfestigkeit der erfindungsgemässen Legierung.4 shows that the alloy according to the invention has a superior warm hardness up to at least 900 ° C. compared to the known cobalt alloy. The comparatively large resistance to deformation at high temperature is characteristic of the heat resistance of the alloy according to the invention.

Die Temperaturwechselbeständigkeit wird günstig beeinflusst durch grossen Elastizitätsmodul und kleinen Ausdehnungskoeffizieten (Fig. 5). Im gesamten untersuchten Temperaturbereich bis 900° C weist die erfindungsgemässe Nickellegierung einen kleineren Ausdehnungskoeffizienten und einen grösseren Elastizitätsmodul auf als die zum Vergleich herangezogene bekannte Kobaltlegierung.The resistance to temperature changes is favorably influenced by a large modulus of elasticity and small coefficients of expansion (FIG. 5). In the entire temperature range examined up to 900 ° C., the nickel alloy according to the invention has a smaller coefficient of expansion and a greater modulus of elasticity than the known cobalt alloy used for comparison.

Der Widerstand der beanspruchten Nickellegierung gegenüber Oxidation (Zunderbeständigkeit) ist gemäss Fig. 6 gross. Das Oxidationsverhalten der neuen Legierung bis 900° C ist mit dem der Kobaltlegierung gleich. Demgegenüber weist die handelsübliche Legierung gemäss DE-PS 2714674 Neigung zur katastrophal Oxidation auf, wie aus dem starken Anstieg der Oxidation oberhalb von 800° C hervorgeht.The resistance of the claimed nickel alloy to oxidation (scale resistance) is high, as shown in FIG. 6. The oxidation behavior of the new alloy up to 900 ° C is the same as that of the cobalt alloy. In contrast, the commercially available alloy according to DE-PS 2714674 has a tendency to catastrophic oxidation, as can be seen from the sharp increase in oxidation above 800 ° C.

Eine Gegenüberstellung von Korrosionswerten . ist der folgenden Tabelle zu entnehmen. Die Prüfergebnisse zeigen, dass die erfindungsgemässe Nickellegierung der Kobalt-Vergleichslegierung überlegen ist im Widerstand gegenüber Schwefelsäure und Salzsäure.

  • Korrosionsverhalten
  • Proben: Gussstäbe 5 mm 0
  • Prüftemperatur: 50° C
  • Gewichtsverlust in g·m-2·h-1
Figure imgb0003
A comparison of corrosion values. is shown in the following table. The test results show that the nickel alloy according to the invention is superior to the cobalt comparison alloy in terms of resistance to sulfuric acid and hydrochloric acid.
  • Corrosion behavior
  • Samples: cast rods 5 mm 0
  • Test temperature: 50 ° C
  • Weight loss in g · m -2 · h -1
Figure imgb0003

Aufgrund ihrer Eigenschaftskombination, insbesondere von Warmhärte, Korrosions- und Zunderbeständigkeit eignet sich die erfindungsgemässe Legierung besonders gut für Kernreaktorbauteile und zum Panzern von Ventilen.Due to its combination of properties, in particular of warm hardness, corrosion and scale resistance, the alloy according to the invention is particularly suitable for nuclear reactor components and for armoring valves.

Claims (6)

1. Highly heat-resistant cobalt-free nickel-iron cast alloy which is imprevious to a change in temperature, in which the components of the structure have great thermodynamic stability, and which moreover has high red hardness, excellent resistance to oxidation, corrosion and wear and good welding properties and is suitable in particular for use as the material for nuclear reactor components, comprising
Figure imgb0007
2. Alloy according to claim 1, characterised by
Figure imgb0008
Figure imgb0009
3. Alloy according to claim 1 with the proviso that
1.1 < % Ceff < 1.6

for % Ceff = % C + 0.86 × % N + 1.11 × % B.
4. Alloy according to claim 2 with the proviso that
1.25 < % Ceff < 1.50

for % Ceff = % C + 0.86 × % N + 1.11 × % B.
5. Use of the alloy according to claims 1 to 4 as the material for nuclear reactor components.
6. Use of the alloy according to claims 1 to 4 as the material for jacketing components which are subjectto wear, such as valves, superheated steam fittings and chainsaws.
EP83101057A 1982-02-27 1983-02-04 Heat resisting nickel-iron alloys for castings with a highly stable structure Expired EP0087609B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3207162 1982-02-27
DE3207162A DE3207162C1 (en) 1982-02-27 1982-02-27 Highly heat-resistant cast nickel-iron alloy with great structural stability

Publications (2)

Publication Number Publication Date
EP0087609A1 EP0087609A1 (en) 1983-09-07
EP0087609B1 true EP0087609B1 (en) 1985-09-25

Family

ID=6156913

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83101057A Expired EP0087609B1 (en) 1982-02-27 1983-02-04 Heat resisting nickel-iron alloys for castings with a highly stable structure

Country Status (4)

Country Link
US (1) US4464335A (en)
EP (1) EP0087609B1 (en)
CA (1) CA1208043A (en)
DE (1) DE3207162C1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4547338A (en) * 1984-12-14 1985-10-15 Amax Inc. Fe-Ni-Cr corrosion resistant alloy
DE10300298A1 (en) 2003-01-02 2004-07-15 Daimlerchrysler Ag Exhaust gas aftertreatment device and method
US8613886B2 (en) * 2006-06-29 2013-12-24 L. E. Jones Company Nickel-rich wear resistant alloy and method of making and use thereof

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB647701A (en) * 1944-02-24 1950-12-20 William Jessop And Sons Ltd Improvements in and relating to nickel chromium steels
GB670555A (en) * 1946-04-12 1952-04-23 Jessop William & Sons Ltd Improvements in or relating to nickel-chromium steels
JPS5040099B1 (en) * 1971-03-09 1975-12-22
FR2346462A1 (en) * 1976-04-02 1977-10-28 Commissariat Energie Atomique HIGH ENDURANCE SUPER ALLOY WITHOUT COBALT APPLICABLE ESPECIALLY IN THE NUCLEAR INDUSTRY
JPS5517403A (en) * 1978-07-24 1980-02-06 Hitachi Ltd Sliding mechanism for control rod

Also Published As

Publication number Publication date
DE3207162C1 (en) 1983-10-06
CA1208043A (en) 1986-07-22
US4464335A (en) 1984-08-07
EP0087609A1 (en) 1983-09-07

Similar Documents

Publication Publication Date Title
DE60023699T2 (en) HOT-REST STAINLESS STEEL AUSTERITIC STEEL
DE69018658T2 (en) High-strength heat-resistant steel with improved machinability.
DE602006000160T2 (en) Heat resistant alloy for 900oC sustainable exhaust valves and exhaust valves made from this alloy
DE69208538T2 (en) Heat-resistant alloy based on nickel
DE69008575T2 (en) Heat-resistant ferritic steel with excellent strength at high temperatures.
DE19941411B4 (en) Turbine or boiler component
DE69112007T2 (en) Ferritic, heat-resistant cast steel and process for its manufacture.
DE2714674C3 (en) Superalloy with high fatigue strength
DE3300392C2 (en)
DE2752529C2 (en) Nickel alloy
DE60103410T2 (en) Inexpensive, corrosion and heat resistant alloy for diesel internal combustion engine
DE2741271A1 (en) NICKEL-BASED SUPER ALLOY AND CAST BODY FROM THEM
DE2534786C3 (en) Nickel-chromium-tungsten alloy and its uses
DE3511860C2 (en)
CH662130A5 (en) COBALT-BASED ALLOY, IN PARTICULAR FOR VALVES AND VALVE SEATS ON COMBUSTION ENGINES.
DE19735361B4 (en) Austenitic stainless steel
DE69907982T2 (en) Materials for welding steel with a high chromium content
DE3903682A1 (en) NITROGEN-REIFIED FE-NI-CR ALLOY
DE2821524C2 (en) Process for the heat treatment of a monocrystalline body made of a nickel superalloy
EP0087609B1 (en) Heat resisting nickel-iron alloys for castings with a highly stable structure
DE69007201T2 (en) Heat-resistant steel can be used for valves of internal combustion engines.
DE2420362B2 (en)
EP0609682B1 (en) Oxidation- and corrosion-resistant alloy based on doped iron aluminide and application of this alloy
DE69112680T2 (en) Corrosion-resistant cast alloy.
DE69110913T2 (en) Car engine parts made of heat-resistant ferritic cast steel with excellent resistance to fatigue from heat.

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): BE FR GB IT

17P Request for examination filed

Effective date: 19831013

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO ROMA S.P.A.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): BE FR GB IT

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
BERE Be: lapsed

Owner name: THYSSEN EDELSTAHLWERKE A.G.

Effective date: 19880228

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19881028

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19881122

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19890228

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST